The present invention relates generally to the data processing field, and more particularly, relates to a method and apparatus for user programmable packet to connection translation in a communications system.
When cells are received in an Asynchronous Transfer Mode (ATM) network or other network, the header is examined to determine a corresponding connection for the received cell. In one known communications adapter, this process is called logical channel descriptor (LCD) translation. In the LCD translation process, predefined VPI/VCI fields are used to generate a LCD index. The LCD index corresponds to a receive connection. This is a simple hardware implemented process in that a configurable number of fixed bits are selected and then the selected bits are concatenated together to provide the LCD index.
In a new communications adapter that supports multiple external physical networks of different types, this simple packet to connection translation is not effective. The physical connections might be ATM connections or different types of packet based adapters like Ethernet, HDLC, Q922.2, FUNI2.0, and the like. The connection of translation logic has become very complex and highly configurable due to different user needs. A different more general method is needed for packet to connection translation.
A principal object of the present invention is to provide an improved method and apparatus for user programmable packet to connection translation. Other important objects of the present invention are to provide such method and apparatus for user programmable packet to connection translation for use with a variety of modes for communications and to provide such method and apparatus that overcome disadvantages of prior art arrangements.
In brief, a method and apparatus are provided for user programmable packet to connection translation. When a data block is received, a protocol type for the received data block is identified. A connection identification is formed utilizing a header of a received data cell, responsive to the identified protocol type for the received data block.
In accordance with features of the invention, an instruction array is used with an arithmetic logic unit (ALU). The protocol type for the received data block is identified based upon the media connection or port number of the received data block. Different code sequences are loaded into the instruction array based upon the identified protocol type for a media connection. The protocol type for a media connection is user programmed or configured.